The PHYSSYS ontology is an ontology that only performs ontology projections. It includes the component, process and EngMath ontologies and relates them to each other. Figure 9 shows the relations between instantiated views on a physical system. Basically, it defines that components are the carriers of physical processes that can be mathematically described with physical quantities and mathematical relations.
Figure 9: Interdependencies between the component, process and mathematical ontologies. Roughly it states that a component is the carrier of physical processes that are described by mathematics.